Field
This disclosure relates generally to semiconductor devices, and more specifically, to test circuitry for insulated-gate bipolar transistors.
Related Art
Power devices are electronic components designed to be tolerant of the high currents and voltages that are present in power applications such as three-phase electric motors, automotive electronics, power supplies, telecommunications, and other applications that require devices to operate at currents in the range of tens up to hundreds of amperes (A).
Insulated-gate bipolar transistors (IGBTs) are designed for power applications and combine metal-oxide-semiconductor (MOS) gate control and a bipolar current flow mechanism. An IGBT incorporates features of both a metal-oxide-semiconductor field effect transistor (MOSFET) and a bipolar junction transistor (BJT). IGBTs have higher current density than MOSFETs and faster switching characteristics than BJTs. IGBTs are a primary choice today for high-power (>10 kW), low to medium frequency (up to 30 kHz) applications.
Over current protection circuitry is often included in devices to protect IGBTs in over current conditions. The protection circuitry detects the over-current condition and prevents the IGBT from operating when the over-current condition is detected. One type of over-current protection circuitry is a de-saturation circuit that detects voltage build-up across the collector and emitter while the device is fully on. If the voltage exceeds a specified limit the associated IGBT is placed in non-active mode.